B). The interest rate on the Term Loan A is based on the sum of either Term SOFR or the Base Rate and an Applicable Rate which varies depending on the current Debt Ratings or Total Leverage Ratio, determined as to whichever shall result in more favorable pricing to the Borrowers (each as defined in the Credit Agreement). The interest rate on the Term Loan B is based on either the Term SOFR or the Base Rate plus an Applicable Rate. The Term Loan A will mature in March 2027 and the Term Loan B will mature in March 2029.
On March 10, 2021, we issued $500 million of 4.500% senior unsecured notes due in March 2029 (the 2029 Unsecured Notes), with interest payable semi-annually. The 2029 Unsecured Notes were sold at 100% of the principal amount with an effective yield of 4.500%. We may redeem all or part of the 2029 Unsecured Notes at the applicable redemption prices described in the Indenture dated March 10, 2021 (the Indenture), plus accrued and unpaid interest, if any, to, but not including, the redemption date.
On March 29, 2022, we issued $600 million of 6.625% senior unsecured notes due in April 2030 (the 2030 Unsecured Notes), with interest payable semi-annually. The 2030 Unsecured Notes were sold at 100% of the principal amount with an effective yield of 6.625%. We may redeem all or part of the 2030 Unsecured Notes, prior to April 1, 2025, at a price equal to 100% of the principal amount of the 2030 Unsecured Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date, plus a “make-whole” premium, as described in the Indenture dated March 29, 2022 (the New Indenture). From and after April 1, 2025, we may redeem all or part of the 2030 Unsecured Notes at the applicable redemption prices described in the New Indenture, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. We may also redeem up to 40% of the aggregate principal amount of the 2030 Unsecured Notes at any time prior to April 1, 2025, at a redemption price equal to 106.625% with an amount equal to or less than the net cash proceeds from certain equity offerings, plus accrued and unpaid interest, if any, to, but excluding, the redemption date.
The 2029 Unsecured Notes and the 2030 Unsecured Notes are subordinated to any of our secured indebtedness, including indebtedness under our credit agreements.
We have a revolving credit agreement with an administrative agent and collateral agent and a syndicate of financial institutions, as lenders (Revolving Credit Agreement) with a maximum borrowing capacity of $450 million. The interest rate under our Revolving Credit Agreement is based on the Adjusted Term SOFR Rate (as defined in the Revolving Credit Agreement). The Revolving Credit Agreement matures in March 2027.
At June 30, 2024 and December 31, 2023, our Revolving Credit Agreement was undrawn, and we had letters of credit, which reduce Revolving Credit Agreement availability, totaling $31.5 million and $27.4 million, leaving $419 million and $423 million available for borrowing at the end of each period. We also had letters of credit and bank guarantees which support certain leased facilities as well as other normal business activities in the U.S. and Europe that were issued outside of the Revolving Credit Agreement for $2.9 million and $3.0 million as of June 30, 2024 and December 31, 2023.
The Revolving Credit Agreement, the Credit Agreement, the Receivables Financing Agreement, the 2024 Notes, the 2029 Unsecured Notes, and the 2030 Unsecured Notes contain cross-default provisions which could result in the acceleration of payments due in the event of default of any of the related agreements. The terms of the applicable credit agreements also require us to maintain ratios for leverage and interest coverage, including on a pro forma basis in the event of an acquisition or divestiture. We were in compliance with our debt covenants at June 30, 2024.