Pulsating low-mass and extremely low-mass white dwarfs (ELMVs; ≲ 0.45 Msun) offer a unique opportunity to probe the internal structure of compact remnants formed in close binary systems. While previous asteroseismic studies focused on small samples, recent discoveries — many of them observed by TESS — now allow for broader exploration. In this work, we present new asteroseismic analyses for several ELMVs, combining light curves from TESS with detailed period-to-period fits. Special attention is given to the hydrogen envelope thickness, which provides key insights into the evolutionary history of these stars.