The 15 to 24 degree Marley Third Round Hip Apex Cap in Grey is used within the Marley Dry Hip System to join third round hips together at the apex and create a sleek finish. The Marley Dry Hip System boasts fast, simple installation and is suitable for all Marley concrete tiles and slates. It provides a weathertight and ventilated mechanical fix for hip tiles, eliminating the need for mortar completely. The Marley Dry Hip System It is compatible with the Marley Ventilated Dry Ridge system and meets BS 5534 requirements and NHBC guidelines.