This 30mm Double Plain Bearing Allenite Through Deck block enables control lines to be guided through a deck or surface with ease. Designed with a durable acetal body to securely hold the sheave, this block is perfect for adjustable rigging and other heavy duty uses. Available in both single and double sheave options, with bearing systems to suit various applications. The double sheave version allows for a maximum 180 degree rope angle. The Plain Bearing design ensures a long lifespan and minimal maintenance.